Roscoe R. Nix, president of the Montgomery County branch of the NAACP, uses a hammer Oct. 27, 1963, to break a bottle of South African wine then stocked in county liquor stores. The former civil rights leader died Jan. 4 of pneumonia. (Douglas Chevalier/WASHINGTON POST)

Roscoe R. Nix, a Montgomery County civil rights leader who used his political influence and confrontational style to draw attention to racial inequities in one of the region’s most affluent jurisdictions, died Jan. 4 at a hospital in Riverdale, Ga. He was 90.

He had Parkinson’s disease and aspiration pneumonia, said his daughter Susan Webster.

Mr. Nix, whose civil rights activism spanned more than a half-century, said his roots in the Deep South defined his outlook on race relations.

Growing up in segregated Alabama had its obvious problems, he said. But the North suffered from “self-righteousness,” he added, and was more likely to overlook its record of discrimination. He vividly recalled being refused service by a Silver Spring restaurant in 1962 and staging a demonstration in response.

While working in various federal government jobs, Mr. Nix won a seat on the Montgomery County Board of Education in 1974 and railed against de facto school segregation. The second African American elected to the board, he served four years.

He remained deeply committed to education while leading the county’s chapter of the NAACP from 1980 to 1990, a period when the organization was struggling to stay relevant to an increasingly successful black middle-class community.

On the school board and afterward, Mr. Nix pushed for greater resources for schools in poorer neighborhoods and spoke out about racial disparities in school suspension rates. He established recognition programs for high-performing black students and encouraged black parents to become advocates for their children.

Roscoe R. Nix Elementary School in Silver Spring was named for him in 2006.

“He was one of the giants in Montgomery County,” said Edward Andrews, superintendent of Montgomery schools in the early 1980s. “Before him, things were business as usual. After him, things were business on behalf of all children.”

With the NAACP, he spoke out against alleged police mistreatment of minorities and worked to get more African American officers on the force.

Politicians who worked with him said he was skilled at building alliances and gaining trust. He also could be confrontational and knew how to attract headlines.

In 1983, he proposed a ban on the sale of South African wine in county-owned liquor stores to protest apartheid.

At a news conference announcing his proposal, he smashed several bottles of wine with a hammer and threatened to picket the house of the county executive, Charles W. Gilchrist (D), if he did not support the ban. Mr. Nix dubbed opponents of the ban “affluent, racist rodents who live in Bethesda, Chevy Chase and Rockville.” He later refused to retract “a single word.”

The ban went into effect, with Gilchrist’s backing.

Mr. Nix also was a loud critic of the conservative majority that swept the school board after he left in 1978. The board advocated a back-to-basics curriculum, closed more than 25 schools because of declining enrollment, and reversed many integration efforts. Mr. Nix battled repeatedly with the board.

Roscoe Russa Nix was born June 22, 1921, in Greenville, Ala., the second of nine children. His father was the only black postman in town.

Mr. Nix attended Alabama A&M University but left to serve in the Army in Europe during World War II.

Afterward, he settled in the Washington area and graduated from Howard University. He moved to Montgomery County in 1968 and then from Silver Spring to Georgia in 2010.

In 1952, Mr. Nix married Emma Coble. Besides his wife, of Riverdale, Ga., survivors include two daughters, Veretta Nix of Lathrup Village, Mich., and Susan Webster of Riverdale, Ga.; a sister, Anita Jackson of Washington; three brothers, Crispus Carey Nix of Montgomery, Ala., Pettis Nix of Tuskegee, Ala., and Comer Nix of Garfield Heights, Ohio; and three grandchildren.

Mr. Nix retired in 1986 from the Justice Department’s Community Relations Service, which focused on conflict resolution in cities experiencing civil unrest. As executive secretary for the Maryland Human Rights Commission in the late 1960s, he promoted minority hiring by state agencies and large companies.

He was regarded as an elder statesman and a confidant to many Montgomery County leaders.

“He was one of the people that you had to go to to get advice and you wanted to go to get advice,” former County Executive Douglas M. Duncan (D) said. “He was very good at telling you what he believed and not good at telling you what you wanted to hear. That’s exactly what you need as an elected official.”

In 2001, Mr. Nix was inducted into the Montgomery County Human Rights Hall of Fame. After receiving the honor, he said, “So much of what Montgomery County is today is because of struggle. . . . It’s hard, especially for young people, to remember how we got where we are today.”